phil@uxh.cso.uiuc.edu (11/21/88)
Calling all vi hacks: When I tried to learn to use vi I ran into one bug that effectively makes vi useless to me. I showed it to several people who, once they saw what it was, said that it could not be fixed. One person suggesting modifying the source. I went back to Emacs instead. This bug works like this: I go into insert mode with "i" and type in some new text. I then backspace over that text with ^H (backspace). The text is no longer in the buffer but is still showing on the screen. To me this is a serious bug because I frequently make mistakes and go back and correct them. I get totally out of whack when I have to work in the blind, or exit insert mode just to see what I am doing (and go back in it again). So, is there anyone out there that knows how to fix this so I can go back to learning how to use vi?
malpass@vlsi.ll.mit.edu (Don Malpass) (11/24/88)
In article <11500001@uxh.cso.uiuc.edu> phil@uxh.cso.uiuc.edu writes: >I go into insert mode with "i" and type in some new text. I then backspace >over that text with ^H (backspace). The text is no longer in the buffer >but is still showing on the screen. I am sure I've seen this, but I think on some machines I've also NOT seen it. Therefore there's some chance it may be a termcap file definition problem. Since it doesn't bug me as much as it does you, the details don't stick in my mind. I'll try to take note of how vi deletions act in the other machines I use, and if there's anything of interest I'll pass it on. Meanwhile, the pointer to termcap may prompt some guru to contribute some wisdom if that's the trouble. -- Don Malpass [malpass@LL-vlsi.arpa], [malpass@gandalf.ll.mit.edu] The Malpass Principle: Given a binary choice, the statistical probability of doing the right thing is 31.7% - on good days.
les@chinet.chi.il.us (Leslie Mikesell) (11/24/88)
In article <11500001@uxh.cso.uiuc.edu> phil@uxh.cso.uiuc.edu writes: >I go into insert mode with "i" and type in some new text. I then backspace >over that text with ^H (backspace). The text is no longer in the buffer >but is still showing on the screen. To me this is a serious bug because >I frequently make mistakes and go back and correct them. I get totally >out of whack when I have to work in the blind, or exit insert mode just >to see what I am doing (and go back in it again). I guess I have just gotten used to this behaviour - thinking back to when I first used vi, it bothered me too. However, it is only a problem when inserting into an existing line, since when you are inserting into an empty line you know that there is no "real" text past the cursor position. Anyway, ESC i will fix everything and is safe to do anytime you want to be in insert mode. The real solution is to learn to use the other vi commands and avoid backspacing beyond the character or word that your cursor is on. For example, if you are several words past the one you want to correct it might be faster to postion back with a search, then use cw to change it, followed by A to get back to the end of the line. This also has the advantage of being repeatable if the word needs to be changed elsewhere. Les Mikesell
kolding@june.cs.washington.edu (Eric Koldinger) (11/24/88)
In article <11500001@uxh.cso.uiuc.edu> phil@uxh.cso.uiuc.edu writes: > >I go into insert mode with "i" and type in some new text. I then backspace >over that text with ^H (backspace). The text is no longer in the buffer >but is still showing on the screen. This isn't a bug, it's just the way 'vi' works. 'vi' is optimized to keep traffic over lines to a minimum, so it's actually a good feature for those of us who use slow telephone lines and dumb terminals to communicate. -- _ /| Eric Koldinger \`o_O' University of Washington ( ) "Gag Ack Barf" Department of Computer Science U kolding@cs.washington.edu
msf@prandtl.nas.nasa.gov (Michael S. Fischbein) (11/24/88)
I tried sending a mail reply, but it bounced.
Try the command :map! ^H ^? ^?
where ^H means backspace, and ^? means delete. Note that these can't be
entered directly, but must be quoted with control-V. To automate them,
put the command in your .exrc or EXINIT.
mike
Michael Fischbein msf@prandtl.nas.nasa.gov
...!seismo!decuac!csmunix!icase!msf
These are my opinions and not necessarily official views of any
organization.aho@cory.Berkeley.EDU (Alex Ho) (11/24/88)
In article <11500001@uxh.cso.uiuc.edu> phil@uxh.cso.uiuc.edu writes: > >This bug works like this: > >I go into insert mode with "i" and type in some new text. I then backspace >over that text with ^H (backspace). The text is no longer in the buffer >but is still showing on the screen. i believe that vi does this so that one can still use the program when working from a slow dumb terminal (at something like 300 baud). to refresh the screen, you can type either ctrl-l or ctrl-r and the screen should refresh. alex. Alex Ho University of California, Berkeley aho@cory.berkeley.edu ...ucbvax!cory!aho
gwc@root.co.uk (Geoff Clare) (11/24/88)
In article <11500001@uxh.cso.uiuc.edu> phil@uxh.cso.uiuc.edu writes: >I go into insert mode with "i" and type in some new text. I then backspace >over that text with ^H (backspace). The text is no longer in the buffer >but is still showing on the screen. To me this is a serious bug because >I frequently make mistakes and go back and correct them. I get totally >out of whack when I have to work in the blind, or exit insert mode just >to see what I am doing (and go back in it again). I haven't seen an answer to this, so I'm posting my suggestion in case it is of use to others. If you could get used to using DELETE instead of BACKSPACE you could map DELETE onto the sequence BACKSPACE-SPACE-BACKSPACE so that the characters are erased on the screen. I have tried this and it works well. (If you use DELETE as your interrupt character, you will need to change it to something else, like CTRL-C, using stty in your .profile/.login). To set it up put the line: map! ^? ^H ^H in your .exrc file. (To enter the text after the 'map! ' you need to type CTRL-V DELETE SPACE CTRL-V BACKSPACE SPACE CTRL-V BACKSPACE). You might also want to use the following mapping so that you can use DELETE in command mode to delete the character to the left. map ^? X Hope this helps. -- Geoff Clare UniSoft Limited, Saunderson House, Hayne Street, London EC1A 9HH gwc@root.co.uk ...!mcvax!ukc!root44!gwc +44-1-606-7799 FAX: +44-1-726-2750
bengsig@orcenl.uucp (Bjorn Engsig) (11/24/88)
In article <11500001@uxh.cso.uiuc.edu>, phil@uxh.cso.uiuc.edu writes: > > I go into insert mode with "i" and type in some new text. I then backspace > over that text with ^H (backspace). The text is no longer in the buffer > but is still showing on the screen. You can use a map! <key> ^H ^H, where a good choise for key could be DEL, if this is not your interupt. Else find some other key that is available. The map! command is used to change the function of a key in insert mode, and the <backspace> <space> <backspace> will provide you with exactly what you want. If you put the map! in your .exrc, remember that you can only enter ^H (and possibly the <key>) by preceeding it with ^V. -- Bjorn Engsig, ORACLE Europe \ / "Hofstaedter's Law: It always takes ..!uunet!mcvax!orcenl!bengsig X longer than you expect, even if you phone: +31 21 59 56 411 / \ take into account Hofstaedter's Law"
pjh@mccc.UUCP (Pete Holsberg) (11/25/88)
Won't ^L repaint the screen so that it matches the buffer's contents?
--
Pete Holsberg UUCP: {...!rutgers!}princeton!mccc!pjh
Mercer College CompuServe: 70240,334
1200 Old Trenton Road GEnie: PJHOLSBERG
Trenton, NJ 08690 Voice: 1-609-586-4800wyle@solaris.UUCP (Mitchell Wyle) (11/27/88)
Map the ^H char to be delete, insert as in: map! ^V^H ^V^?i -- -Mitchell F. Wyle wyle@ethz.uucp Institut fuer Informatik wyle@inf.ethz.ch ETH Zentrum / 8092 Zurich, Switzerland +41 1 256 5237
les@chinet.chi.il.us (Leslie Mikesell) (11/30/88)
In article <492@solaris.UUCP> wyle@ethz.UUCP (Mitchell Wyle) writes: >Map the ^H char to be delete, insert as in: >map! ^V^H ^V^?i Doesn't work here. If you happen to have done an "stty erase '^?'" it does at least delete a character, but it leaves you in a different place depending on whether you were at the end of a line or not. I think that you really need <esc>xa if you are at the end of a line, <esc>xi otherwise. Anyone else have a solution? Les Mikesell
kevin@stl.stc.co.uk (Kevin Lewis) (12/01/88)
In article <7032@chinet.chi.il.us> les@chinet.chi.il.us (Leslie Mikesell) writes: >In article <492@solaris.UUCP> wyle@ethz.UUCP (Mitchell Wyle) writes: >>Map the ^H char to be delete, insert as in: >>map! ^V^H ^V^?i > >Doesn't work here. If you happen to have done an "stty erase '^?'" it >does at least delete a character, but it leaves you in a different place >depending on whether you were at the end of a line or not. I think that >you really need <esc>xa if you are at the end of a line, <esc>xi otherwise. The real problem here is that once you come out of the current insert or append, and enter another one, you can't delete past the beginning of the insertion. This means that you can only delete on character at a time, but you can continue inserting. Any answers out there? Myself, I'm happy with mapping delete to ^H ^H, as I don't mind the text not moving backwards. kev ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Kevin Lewis STC Technology Ltd +44 279 29531 ext 2579 London Rd Email: kevin@stl.stc.co.uk Harlow CM17 9NA ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
olsen@amelia.nas.nasa.gov (Michael E. Olsen) (12/10/88)
In article <11500001@uxh.cso.uiuc.edu> phil@uxh.cso.uiuc.edu writes: > >Calling all vi hacks: > >This bug works like this: >I go into insert mode with "i" and type in some new text. I then backspace >over that text with ^H (backspace). The text is no longer in the buffer >but is still showing on the screen. This is my favorite editor, and I have seen various incantations of it in my travels. The mapping tricks to get destructive backspace are fine if they work, but I believe the "elegant" solution is to :se redraw which will either do nothing at all (most versions of the editor) or will (and I quote) "simulate a smart terminal". I think this feature is usually made to do nothing so that (as others have noted) the editor transmits as few characters as possible. On some of the UNIX systems I have seen a version of vi which is invoked as "vedit", let you know when you're in insert mode, etc. with prompts at the bottom of the screen. If you're learning, or if you have a limited memory for editor fine points like I do, I heartily suggest you obtain a vi "cheat sheet" (mine is titled Ex Quick Reference of course). I have used the editor for a while now, and I still am amazed at all the features I can forget in between perusals of this sheet.
phil@uxg.cso.uiuc.edu (12/21/88)
Thanks for all the posting and e-mail about vi. The responses varied over quite a wide range from "it works as designed" to "here's how to fix it". Sorry I haven't had time to actually try out any suggestions. I might have that time in the next couple of weeks (hopefully). Consider an editor environment (not necessarily emacs) where something is mapping keystrokes into editing functions, and something ELSE is constantly reading the file buffer and updating the screen to make the changed buffer always appear on the screen. The screen updating has nothing to do with the commands being executed. The only influence they have on the screen is the active window and cursor position, and the buffer contents. If I build a key map to function that works just like vi, it will NOT display just like vi. I am working on just such a thing as an integral part of a smart terminal program for my personal computer. If such a thing existed for YOUR personal computer, would it bother you that the display would always show precisely what is in the file buffer as fast as the screen can be updated (usually very fast)? In an attempt to modularize this program, this is the result I get.